Soft Shadows

Soft Shadows

Soft Shadows is a tool in SpaceDesign to create an image from SketchUp with softer shadows from the sun.

This is accomplished by merging images with sun sun set to slsightly different dates and times.

This is a SketchUp model using a Sketchy Style. However the shadows are too harsh.
This is the same model processed by SpaceDesign Soft Shadows.


Quick Setup Tab

To get started, select a softness and coarseness below.
Use Medium and Medium for your first trial - it will merge about 25 images.

Sketchy Shadows do not work on the ground plane - you must have a face to cast Sketchy Shadows onto.

Use other tabs for more advanced settings.

Presets The Shadows Tab provides a set of presets for Softness and Width of the shadow images.

Shadow Softness - None, Coarse, Medium, Smooth or Custom - sets number of iterations.
Shadow Spread - Narrow, Medium, Wide or Custom - sets days and time to process.

Quick Shadow Mode

  • Soft Shadows - creates a soft shadow with a solid color.
  • Sketchy Shadows - creates a default Sketchy Shadow
  • Use Advanced - uses advanced settings from the Shadows or Patterns Tab.

Soft Shadows Tab

Presets - see Quick Setup above.

Shadow Processing

Shadows and surfaces in shade - all areas not in direct sun will be treated as shadowed areas.
Shadows only - only areas which have full shadows when the sun is on will be processed.

Shadow masking

None - all shadows are merged to create the soft shadow image.
Shadows only - mask to original shadow area
Will only soften shadows where shadows appear in original image.
(Otherwise soft shadows will make the overall shadow area larger.)
Sun Only - soft shadows are only processed in areas originally not in shadow.

Shadow mode

Inverse Shadow Mode. White hatch in sun, no hatch in shadows.
Normal - apply color or pattern to shadows
Inverse - white patterns to non-shadow areas
Both - apply color of pattern to all areas

Darkness/Opacity This changes the darkness of the shadows. the shadow pattern will be partially transparent, allowing the colors below it to bleed through.

Darkness = 50%
Darkness = 100%

Wash out base image Makes the base image lighter, before applying the shadow texture.

No wash
50% wash

Custom Settings

  • Number of iterations for date and time
If you enter 5, then 25 ( 5 x 5) images will be blended - with 5 different dates and 5 different times.
  • Date increment (days) - Number of days separation for each iteration.
If set to 0, then date iterations will not be used.
You can set it to a fraction, such as 0.5. This will create fewer date iterations. (You cannot move by 1/2 day, but the iterations with the same date will be skipped)
  • Time increment (minutes) - Number of minutes separation for each iteration.
If set to 0, then time iterations will not be used.



This, somewhat crude, image was created with 3 iterations (9 images), 2 days per iteration, and 30 minutes per iteration.
(A "crude" image like this will work OK for Sketchy Shadows.)
This image was created with 8 iterations (64 images),
1 day per iteration, and 10 minutes per iteration.
This image was created with 10 iterations (60 images - because date iteration was only 0.5), 0.5 day per iteration, and 5 minutes per iteration.

SkethUp Watermark Styles

Soft Shadows also works with watermark SketchUp styles. This image was made using the NrpTools Crayon style. The watermark mostly, only appears in the dark, (shadowed) areas of the model.

Use only full shadows

All areas not in direct sunlight treated as in shadow.
(Use only full shadows unchecked)
(Image is using Chipboard Shadow Color Mode and Blue color)
Only area darkened when sun it turned on treated as in shadow.
(Use only full shadows checked)A
Wall which is technically in the shadow of the sun, is not treated as a shadowed area.


You can specify a Chipboard texture, or you can select an image to use as a texture. The texture image will be applied to the shadows directly, and not applied to the surfaces in your model. This means that the texture will not rotate to match surfaces, and will not get smaller in the distance.

Here is a sample of a Soft Shadow pattern, and a similar Sketchy Shadow material.

Soft Shadow Texture Pattern - applied uniformly across image.
Scale factor 0.01
Sketchy Shadow Texture - pattern is applied to model first, and then to shadows.
Note that the pattern changes to match the planes of the surfaces in the model, and that the pattern gets smaller as it moves away from the eye.
Scale factor 1.0

Masking to original shadow area

Sometimes when you add a lot of days or time, the soft shadows start to get to wide. You can specify that the soft shadows are restricted to the original shadow shape. This lets you create very soft shadows in large areas by masking the shadows to the original shadow area.

Check Mask to original shadow area to achieve this effect.

Original shadows from ShetchUp
Soft Shadows over a wide area. (I used just a few iterations so you could see the effect better
Soft Shadows masked to original shadow shape.

Soft Sun

Similar to the idea of masking the Soft Shadow effect to the original shadow area, is the ability to mask it to the original area not in shadows. This works best with interior images.

Soft Shadow effect masked to area already lit by the sun. You get a sharp boundary, but a soft effect for the sunlight itself.

Shadow Study

Shadow study averaging one image per month

You can use this to make a shadow study showing average shadows for the year

Set days to 365 and time to 0 for just one image per day.

Use with Sketchy Shadows

Soft Shadows can also be used with Sketchy Shadows to soften the Sketchy Shadow patterns.

Soft Shadows and Sketchy Shadows combined.

Other examples

Nail Image in SkectchUp.
10 iterations, 0.25 days, 4 minutes

See also